An accelerator pedal accelerates the rotation of an engine. It is necessary to step on the accelerator pedal in order to accelerate by increasing the engine speed, and is necessary to release the foot from the accelerator pedal in order to decrease the engine speed. The accelerator pedal is connected to a throttle valve via the wire and linkage. Stepping on the accelerator pedal, the throttle valve is opened and air is inhaled into the cylinder. Then, the electronic control fuel injection device detects the amount of the air and supplies gasoline suitable for the operation state of the engine.
The accelerator pedal includes a mechanical accelerator pedal and an electronic accelerator pedal. In the mechanical accelerator pedal, the accelerator pedal is mechanically connected to the throttle valve of the engine by a cable. In the electronic accelerator pedal, the position of the pedal is sensed by a sensor and the operation of the throttle valve is controlled based on the sensed position signal.
The mechanical accelerator pedal causes problems in its operation due to ambient environments, temperature change, degradation of the cable, etc. Accordingly, at present time, the mechanical accelerator pedal has been replaced with the electronic accelerator pedal. Since the electronic accelerator pedal does not require the cable, it has a sufficient space for installation, reduces the fatigue of a driver and improves the fuel efficiency.
However, the driver has a preference for a tactile response that the driver feels from the conventional mechanical accelerator pedal. Also, hysteresis must be generated so as to relieve the driver's fatigue caused by the operation of the electronic accelerator pedal.
A method for generating the hysteresis which is applied to a conventional electronic accelerator pedal has a structure friction method, a housing friction method, etc. However, these methods have a complex structure and require a great number of parts.